• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1010-1016
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• 1999

We synthesized the photoresponsive side chain polymers containing aminonitro azobenzene for studying the effect of temperature on photoinduced birefringence. Four different copolymers were prepared using methacrylate, α-methylstyrene, and itaconate monomer. Photoisomerization was observed under the exposure of UV light using UV-VIS absorption spectroscopy. Reorientation of polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532 nm. The change of the birefringence was observed with increasing the sample temperature under a continuous irradiation of excitation light. We could estimate the activation energy of molecular motion in thermal and photochemical mode. Besides the effect of glass transition temperature on the activation energy, we focused our interests on the effect of geometrical hindrance of polar azobenzene molecules and cooperative motion of environmental mesogenic molecules in the vicinity of polar azobenzene molecules.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.121-122
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• 2003

In this study a microchannel with various arrangement of blocks is newly proposed. This design comprises periodically arranged simple blocks. In this configuration, the stirring is greatly enhanced at a certain geometric parameter set. To characterize the flow field and the stirring effect both the numerical and experimental methods were employed. To obtain the velocity field, three-dimensional numerical computation to the Navier Stokes equations are performed by using a commercial code, FLUENT 6.0. The fluid-flow solutions are then cast into studying the characteristics of stirring with the aid of Lyapunov exponent. The numerical results show that the particles' trajectories in the microchannel heavily depend on the block arrangement. It was shown that the stirring is significantly enhanced at larger block-height and it reaches maximum when the height is 0.8 times the channel width. We also studied the effect of the block stagger angle, and it turns out that the stirring performance is the best at the block angel ${45^\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.257-263
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• 2011

Recently as AR(Augmented Reality) is focus of attention, AR is applied to various fields and is expected its valuable use. In this paper, we implemented the system based on Goblin XNA which supports high resolution model file and higher AR. We confirmed the relation of model output among the number of marker, the location and changes of camera distance. And we produced the infantile studying contents using AR and embodied. In implemented contents, we showed the familiar character to infants on each page marker. As the result of it, we can raise their concentration and at a time studying supporters can use the contents easily as well. Also we put 3 marker on each page of contents to recognize it smoothly in case one part of it is hidden by any obstacle. Finally we maximized the learning effect such as presence and immersion in studying through reinforcing 3D models according to the every situation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1609-1620
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• 2011

The purpose of study is to examine the effects of the reading discussion-oriented career exploration program for elementary school students on career development and achievement motivation. To achieve this purpose, three fifth grade classes were assigned to an experimental group, comparative group A and comparative group B. Reading discussion-oriented exploration program for the experimental group was conducted for five weeks in ten sessions, the same period of time for comparative group A was given for conducting a career education program and subject studying was conducted on comparative group B. The results of this study, the experimental group applied to the reading discussion-oriented career exploration programs showed a significant increase in their career development compared with the subject studying group. But they did not show a significant increase compared with the career education group. Second, experimental group applied to the reading discussion-oriented career exploration programs showed significant increase their achievement motivation compared with the subject studying group and career education group.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.819-828
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• 2011

This research was done to clarify the cooling effect of water particles generated from a fountain. This effect is a one way to control the heat island effect of big cities. The result of this research was drawn by setting the jets of water in a certain height, and then studying the diffusion of water particles, which is affected by the size of the particles and the wind speed, and the cooling effect caused by the diffusion. 1) When a diameter of a water drop was 500 ${\mu}m$ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 75 to 190m, and the water vapor spread over 175 to 440 m. As a result, there was more than $0.5^{\circ}C$ of cooling effect on the temperature in the atmosphere 130 to 330m around the water fountain. 2) When a diameter of a water drop was 750 ${\mu}m$ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 65 to 150 m, and the water vapor spread over 160 to 405 m. Moreover, there was more than $0.5^{\circ}C$ of cooling effect on the temperature in the atmosphere 110 to 275 m around the water fountain. 3) After studying on the relationship between the diameter of water drop and the wind speed, and the diffusion of water particles and the range of the atmosphere that was cooled, a result could be drawn from the research that the smaller the diameter of the water vapor gets and the faster the wind speed becomes, the wider the water particles diffuse and the cooler the atmosphere around the fountain becomes. 4) This research further extrapolates that when the ordinary water(tap water, water from river and stream) is used in a fountain, the cooling effect of the air near the fountain can be approached similarly. If the seawater is used in a fountain, there is to be more to concern not only on cooling effect on the air, but also on other effects on surrounding environment generated by the salt in seawater.

• Journal of Family Resource Management and Policy Review
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• v.20 no.4
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• pp.35-47
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• 2016

This research aimed to observe adolescent children's use of time and to discover the parent-related factors that affect adolescent children's use of time. The subjects included 2,092 fourth-grade elementary school students and 2,108 first-grade middle school students. We used data from the Korean Children and Youth Panel Survey. We tested sociodemographic factors, parents characteristics, and time usage, and we studied these factors using SPSS version 23.0; the results are as follows. Firstly, in the subordinate scope of the child-rearing attitude of parents, affection fourth-grade elementary school students(M = 1.83) and first-grade middle school students(M = 2.02). Inconsistency had an effect on fourth-grade elementary school students(M = 1.99), and first-grade middle school students(M = 2.12). Excessive expectations had an effect on fourth-grade elementary school students(M = 2.40) and first-grade middle school students(M = 2.55). Over-involvement had an effect on fourth-grade elementary school students(M = 2.68)and first-grade middle school students(M = 2.80). Finally, giving reasonable explanations had an effect on fourth-grade elementary school students(M = 1.51)and first-grade middle school students(M = 1.68). Secondly, in fourth-grade elementary school students(M = 463.35) and first-grade middle school students(M = 378.75). Further, studying hours during weekdays had an effect on fourth-grade elementary school students(M = 456.15) and first-grade middle school students(M = 460.86). Free activity hours during had an effect on fourth-grade elementary school students(M = 390.54) and first-grade middle school students(M = 387.11). Sleeping hours during holidays had an effect on fourth-grade elementary school students(M = 544.85) and first-grade middle school students (M = 511.74). Studying hours during holidays had an effect on fourth-grade elementary school students (M = 484.86) and first-grade middle school students (M = 511.74). Free activity hours during holidays had an effect on fourth-grade elementary school students(M = 518.68) and first-grade middle school students(M = 509.73). Thirdly, by observing the relative influence of related factors on adolescent children's use of time, grade(${\beta}$ = -.284), gender(${\beta}$ = -.208), over-involvement(${\beta}$ = -.380), supervising(${\beta}$ = -.217), and (${\beta}$ = .243) in terms of the child-rearing attitudes of parents was found to affect study hours($F=2.595^{**}$). The education level of fathers(${\beta}$ = -.144) results in(${\beta}$ = 1.991) and longer free activity hours for children($F= 4.116^{***}$). This research can be used to study the influence of parents'child-rearing attitudes on adolescent children's use of time and to suggest the role of parents in adolescents' ability to manage time effectively using practical.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.73-79
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• 1999

Finite element equations by using fast Fourier transformation were formulated for studying temperatures resulting from frictional heating in sliding systems. The equations include the effect of velocity of moving components. The program developed by using FFT-FEM that combines Fourier transform techniques and the finite element method, was applied to the sliding bearing system. Numerical prediction obtained by FFT-FEM was in an excellent agreement of experimental temperature measurements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.392-393
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• 2009

The study is aimed at studying a weakly relativistic oversized BWO with a Bragg reflector entrance of SWS. The Bragg reflector reflects microwaves, while it is open for beam propagations. By changing the boundary condition at the beam entrance, the effect of the Bragg reflector on the BWO performance is examined.

• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.119-128
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• 1997

Added variable plot and component-plus-residual plot are very useful for studying the role of a predictor in classical regression analysis. The former is usually used to check the effect of adding a new variable to existing model. The latter has been suggested as computationally convenient substitutes for the added variable plots, however, this plot is found to be better in detecting nonlinear relationships of a new predictor. By combining these two plots dynamically, we can take advantages of two plots simultaneously. And even further, we can get some knowledge of collinearity between a new predictor and predictors already in the model, and more accurate information about the possible outliers.

• Journal of the Korean Statistical Society
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• v.4 no.2
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• pp.139-151
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• 1975

Individual effect of genes controlling quantitative traits can not ordinarily be distinguised from one another. Consequently, it is not possible to determine the mode of inheritance for single genes. By studying their combined effectsin segregating generations, however, one can gain some insight into their behavior and can make statistical inferences about their average gene action. The investigation reported herein was to extend genetic variance components and variance and covariance analyses, special attention was given to the genetic statistics from which least square estimators of genetic parameters are obtained.